Mechanical pencil



ug. 6, 1929., R KEERAN L'YEJV MECHANICAL PENCIL Filed March 24, 1926 ,Z'S ZZZOJGS.

`carried and within said atente ug. 6, 1929.

STATES CHARLES R. KEERAN, OF CHICAGO, ILLINOIS.

MECHANICAL PENCIL.

.application led March 24:, 1926. Serial No. 96,975.

rlhe purpose of this invention is to provide an improved construction for a mechanical pencil in which t-he lead-feeding or propelling mechanism shall be simple and economical to manufacture; another object is to provide for the use of a maximum length of lead while permitting such leads to be loaded in the pencil without the usual danger of breakage. The invention consists in certain elements and features of construction in combination, as herein shown and described, and as indicated by the claims.

In the drawings:

Figure 1 is an axial section of a mechani cal pencil embodying this invention.

Figure 2 is an enlarged sectional view showing the lead-propelling mechanism adjacent the tip of the pencil.

Figure 3 is a transverse section taken as indicated at line, 3-3, on Fig. 1.

Figure et is a detail of the removableA feed plunger with its guide tube and operating head.

Figure 5 is a side elevation partly in section showing a slightly modified construction for using an ornamental composition barrel.

As shown in Figure 1, the barrel, 1, of the pencil is formed with the usual tapered portion 1a, at one end, swedged down to form a tip 1", which is axially bored to fit the pencil lead, 2, and is preferably split to provide a frictional grip upon the lead. fithin the barrel, 1, is mounted a tube, 3, which is internally threaded, the thread being preferably formed by pressing or rolling it into the material of the tube, 3. Said tube issecured in the barred, 1, by means of plugs, 4 and 5, which may be soldered or sweated in plate and similarly atlixed to the outer surface of the tube, 3. One end of the tube extends into the taperedportion, 1, of the barrel to the point at which it fits snugly therein and the' opposite end terminates in the plug, 5, flush with the end of the barrel. 1.

1Within the threaded tube,

3, a longitudinally slotted guide tube, 6,

is rotatably guide tube is n1ounted a plunger pin, 7, having a flattened portion, 7, swedged thin enough to extend through the slot, 6a, of the tube, 6. This part, 7a, is shaped to serve as a follower engaging the threads of the tube, 3, being preferably formed with two rounded teeth or projections as shown in Figure 2 so that when the slotted tube, 6, is rotated within the threaded tube, 3, the plunger, 7, will be moved axially within the guide tube, t3. For thus rotating the tube,'6, it is fixed in the head, 8, of the pencil by securement with solder or the like in a plug, 9, which in turn is fastened into the cylindrical head, 8, by engagement of its grooved periphery with an inwardly pressed bead, 10, formed in the head, 8. "llhe end portion, 1, of the barrel, 1, may be reduced as shown in Fig. 1, to receive the head, 8, and the latter will be held -frictionally in engagement with the barrel, 1, at this telescoping connection.

,Rotation of the head, S, on the barrel, 1,

turns the guide tube, 6, within the threaded tube, 3, and advances the plunger, '7, for feeding the lead, 2, through the split tip at 1D. The annular space, 11, between the threaded tube, 3, and the barrel, 1, is adapt-ed to serve as a magazine for holding a quantity of extra-A leads indicated at 2n. rlhese leads are accessible through openings, 12, in the plug, 5, while the presence of the plug, t, prevents them from becoming wedged in the tapered portion, 1", of the barrel. The head, 8, is retained on the barrel, 1, solely by the friction of its telescopic engagement therewith hence to gain access to the magazine it is only necessary to pull olf the head, 8, thus uncovering the openings, 12, in the plug, 5, The guide tube, 6, and itsI plunger, 7, are removable as a unit with the head, 8.

For inserting a new lead the head, 8, with guide tube, 6, are removed and the lead taken from the supply at 2, is inserted into the upper end of the threaded tube, 3, that it slips down therein and is directed into the close fitting bore of the tip at 1b. The guide tube, 6, is then replaced within the tube, 3, and to facilitate engagement with the. end of the lead the free end of the tube, 6, is preferably flared as shown at G". As the tube, 6, is inserted the follower, 7a, will catch against the first thread of the tube, 3, and will slide toward t-he end of thetube, 6, which is attached to the head, 8. As the head, 8, is slipped over the reduced portion, 1c of the barrel the plunger pin, 7, will be brought near to the upper end of the lead and by one or two turns of the head, 8, the plunger will be fed into engagement with the lead for pushing the latter through the Cit tube, 1b, into writing position. Thereafter the wear of the lead taken up as required and by turning the head, 8, to feed the follower, 7, and the plunger, 7, downwardly in the guide tube, 6.

Figure 5 shows a slight modification in the construction in which the tapered portion, l, of the barrel terminates adjacent the plug, 1, and tits over the reduced end portion, 15, ot a composition barrel, 15, which may be used instead of a unitary metal barrel as indicated in Fig. 1. At the other end the composition barrel, '15, is reduced again atv 15", providinga portion which corresponds to the part, 1C, in Fig. 1, :tor receiving the rotatable head, 8. In other respects the construction may be similar to that shown in Fig. 1. The outer end of the head, 8, is an open cylinder intended to receive an eraser, 13, which is made up with an att-ached metal sheath, 14, which slips` snugly into the open end of the head, 8, and is frictionally held therein. IVhen the eraser, 13, has worn down even with the head, 8, it may be pushed out of the head by the insertion of a pin or wire through one of lthe openings, 9, formed in the plug, 9,

which serves as the bottom of the eraserholding recess.

I claimt- 1. In a pencil comprising a barrel, an internally threaded tube fixed axially therein, a longitudinally slotted tube rotatably carried in the threaded tube, a plunger in the slotted tube having a follower which projects through the slot for engagement with the threads of the other tube, said slotted tube having means attached to one end accessible outside the barrel forrotating the tube and for withdrawing said slotted tube axially from the barrel, the end of the slot being closed adjacent the other end ot the tube to retain the follower, and the extreme end portion of the slotted tube being flared t-o Afacilitate engagement with the lead as said tube is inserted in the barrel.

2. In a pencil comprising a barrel, an internally threaded tube. spaced from and fixed axially therein, a longitudinally slotted ftube rotatably carried in the threaded tube,

a plunger in the slotted tube having a "tollower which projects through the. slot for engagement with the threads of the other tube and a head fixed to one end of the slotted tube teleseopically engaged with one end of the barrel, whereby the slot-ted tube maybe rot-ated in the barrel by means of? said head or may be withdrawn with its head and plunger' as a unit.

In a pencil comprising a barrel having an axial opening extending from end to end and an internally threaded tube extending substantially throughout the length ot the barrel spaced from and axially fixed therein, a slotted guide tube rotatably carried w'ithin the threaded tube and a relatively sho: t plunger in the guide tube having a flattened portion projecting through its lslotl for ein gagement with the thread of the. other tube, together with a head fixed to the end of the slotted tube and rotatably and removably engaged with the barrel, whereby the slotted tube may be withdrawn axially by removal ot the head, and a lead nearly as long as the barrel may be inserted from the end uncovered by removal of the head.

4. In a pencil comprising a barrel and a removable head thereon having a lead-propelling mechanism fixedly attached to said head, an eraser pocleted in-the head and an opening accessible from the same side ot the. head to which the propelling mechanism is secured to permit the insertion ot means for ejecting the eraser from the head.

5. In a pencil comprising abarrel,` a removable head thereon having lead-propelling mechanism attached to said head, said mechanism co-operating with a threaded tube axially fixed in and spaced from said barrel, whereby to define an annular spare lead chamber thereabout.

(3, In a pencil comprising a barrel, a removable head thereon having lead propelling mechanism attached to said head. said mechanism having engagement with a threaded tube axially fixed in and spaced from said barrel, whereby to define an annular spare lead chamber thercabout extending the length of the barrel.

7. In a pencil comprising a barrel, an internally threaded tube spaced from and fixed axially therein whereby to define an annular 'chamber about said tube, a longitu dinally slotted tube rotatably carried in tht` threaded tube, a plunger in the slotted tube having a follower which projects through the slot'y for engagement with the threadsl ot the other tube, and a head fixed to one end of the'slotted tube. and removably engaged with one end ot the barrel so that the slotted tube with its head and plunger may be withdrawn as a unit from said barrel, said chamber being accessible by the removal of the slot-ted tube from the. barrel.

S. In a mechanical pencil having a barrel and a tapered tip, an internally threaded tube securedin said barrel in spaced -relation to define an annular chamber about the tube, and extending into the tip, and mechanism co-operating with the tube for feeding a. lead through the tip.

CHARLES R. KEERAN.

Cil 

